Aliso Canyon Update

Saddlebridge Fire Results

On October 14, 2019, South Coast AQMD was notified of a fire at the Aliso Canyon natural gas storage facility. Inspectors were dispatched and joined representatives of the Los Angeles County Fire Department Health Hazardous Materials Division (HazMat), the Division of Oil, Gas & Geothermal Resources (DOGGR), the Department of Public Health, the California Public Utilities Commission (CPUC), and So Cal Gas at the site. The fire was extinguished on October 15.

South Coast AQMD has taken canister air samples in the vicinity of the small area onsite. Results from those samples included methane and other lighter hydrocarbons. Additional results will be posted when available. South Coast AQMD also took air samples and conducted mobile methane monitoring in the community. Data from the mobile methane monitoring show readings to be typical of ambient levels (about two parts per million). Results from the canister sample collected in the community show no elevated levels of hydrocarbons or other VOCs.

Both HazMat and SoCal Gas took additional air and soil samples which are undergoing independent testing.

The source of gases is still unknown and under investigation. South Coast AQMD, along with state and local agencies, will continue to monitor the situation.

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Laboratory Results

 Lab ID  Sample Date  Description
1929404 Sat., Oct. 19, 2019 Canister sample location #1
1929405 Sat., Oct. 19, 2019 Canister sample location #2
1929406 Sat., Oct. 19, 2019 Canister sample location #3
1929407 Sat., Oct. 19, 2019 Canister sample location #4

Recent & Upcoming Activities


Aliso Canyon Natural Gas Well Sealed

Southern California Gas Company (SoCalGas) operates the Aliso Canyon natural gas underground storage facility at 12801 Tampa Avenue in Northridge, CA 91326. On October 23, 2015 SoCalGas discovered that Well SS25 used to inject and withdraw natural gas from the underground storage reservoir at their Aliso Canyon facility was leaking.  On February 18, 2016, the California Department of Conservation, Division of Gas and Geothermal Resources (DOGGR) provided notice to the public confirming that Well SS25 at the Aliso Canyon Gas Storage Facility had been successfully sealed.

South Coast Air Quality Management District (South Coast AQMD) and California Air Resources Board (CARB) staff jointly developed a set of criteriaLink to external determine when air quality in the surrounding communities of the Aliso Canyon facility has returned to typical conditions -  a checklist to determine when the air quality is no longer being impacted as a result of the leak.  Click on the following links for information about:

South Coast AQMD staff continues to observe and monitor operations at the Aliso Canyon facility and the surrounding community and to conduct ambient air measurements both within the facility and offsite in Porter Ranch and surrounding communities. 

Additional Air Monitoring and Inspection Activities

On July 31, 2017, SoCalGas (SCG) resumed natural gas injection operations at its Aliso Canyon storage facility.  As one of the conditions for resuming injection activities, aerial measurements of methane emissions from the facility were conducted by a third party contractor earlier that week. Airborne surveys on July 27 and August 3, 2017 revealed the presence of increased methane emissions from the northwest portion of Aliso Canyon.

In response to this finding, starting on July 28, 2017, South Coast AQMD staff from the Office of Compliance & Enforcement and Atmospheric Measurement were dispatched to investigate the cause of these elevated aerial measurements, and mobile methane surveys resumed within and outside of the SCG property line, to include within The Termo Company (Termo), and in the surrounding communities. While inspectors and atmospheric measurements staff detected, identified, and verified repairs of specific leaks from various components at both Termo, and SCG, so far, no obvious emission sources associated with renewed injection operations have been detected by South Coast AQMD staff.  

Mobile surveys in Porter Ranch and other neighboring communities have consistently shown methane readings close to typical ambient levels. South Coast AQMD will conduct additional mobile surveys and follow-up inspections at both Termo, and the SCG Aliso Canyon facility, and in the surrounding communities. Mobile methane survey results and updates are posted on our website.

Final Air Monitoring Results

An Executive Summary and a final technical report summarizing the air monitoring results from all fixed site and mobile measurements conducted by CARB and the South Coast AQMD between October 2015 and June 2017 have been prepared:

Compliance/Enforcement Activities

News Releases


Report odors similar to the sulfur (rotten egg) smell of natural gas to 1-800-CUT-SMOG (1-800-288-7664) or through the On-line Complaint System.  If  you otherwise believe there is a problem related to natural gas, please also contact SoCalGas at 1-800-427-2200.

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